1. Field of the Invention
The present invention relates to a mobile communication system, and in particular, to a method for concurrent multiple services on the interfaces between a BSC (Base Station Controller) and a MSC (Mobile Switching Center).
2. Background of the Related Art
As widely known in the prior art, a digital mobile communication network such as a Digital Cellular Network (DCN) or a Personal Communications Service (PCS), which are second generation mobile communication systems, can provide only one service to one mobile station at the same time and also can process only one service in a call processing mechanism for service. Therefore, a specific service in use can be switched into another type of service through service negotiation on the radio interface and call processing, but the current service would inevitably be stopped.
Concurrent service is a function in which a subscriber can be further provided with a new service while using the current service, without interrupting the current service. The subscriber can therefore be provided with a plurality of services, including voice and data service, at the same time. The concurrent service, however, cannot be provided by the call processing mechanisms and procedures provided by the second-generation mobile communication system such as DCN or PCS.
At present, the method for providing concurrent multiple services in a cdma2000 system is limited to the TIA/EIA/IS-2000A, which is a cdma2000 radio interface standard. However, a method for controlling concurrent service in the BSC and the MSC has not yet been defined. The procedures and message structures related to the concurrent service in the interface between the BSC and the MSC are not defined either.
Hereinafter, the procedures between the mobile station and the base station and the base station controller are assumed to follow the TIA/EIA/IS-2000A standard, thereby omitting a detailed description thereof, for the purpose of explanation.
FIG. 1 shows a related art method for setting No. 7 SCCP (Signaling Connection Control Part) connection between a BSC and a MSC.
Referring to FIG. 1, the current second generation digital mobile communication system is required to follow the call setup procedures corresponding to each service including voice, data, etc., to provide a specific single service. In particular, the system sets up one No. 7 SCCP for a call to provide the requested service, and discriminates the corresponding mobile station with SLR/DLR (Source/Destination Local Reference Number) allocated thereto to control the service between the BSC and the MSC.
Specifically, upon receiving an Origination/Page Response message on the radio interface that initiates the mobile originating/terminating call setup procedure, the BSC allocates a No. 7 SLR to uniquely identify the signaling connection in the interface between BSC and MSC, and constructs a Complete Layer 3 Information message, including a CM (Connection Management) Service Request/Page Response message in the IOS (Inter-Operability Specification) for initializing call processing of a corresponding mobile station. Then, the BSC transmits the No. 7 SCCP Connection Request message, including an IOS Complete Layer 3 Information message and SLR, to the MSC for the establishment of an SCCP signaling connection (S10).
When the BSC receives a SCCP Connection-Confirm message for confirming the SCCP connection establishment from the MSC, the SCCP signaling connection for the corresponding mobile station is completely established on the interface between the BSC and the MSC. Here, the SCCP Connection-Confirm message includes the connection SLR/DLR, which has been maintained until a service to the terminal is stopped and is applied to control the call (S11). It is the responsibility of the BSC and MSC to insure that no two calls have identical SCCP local reference numbers.
FIG. 2 shows a related art method for using the No. 7 SCCP connection SLR/DLR between the BSC and the MSC.
FIG. 2 describes additional detail of the control message for the corresponding mobile station, which includes the SCCP connection identifier SLR/DLR in the previously established SCCP connection state. As shown in FIG. 2, the control message transmitted from the MSC to the BSC includes the SLR (MSC)/DLR (BSC), and the control message transmitted from the BSC to the MSC includes the SCCP connection SLR/DLR, which are composed of SLR (BSC)/DLR (MSC).
FIG. 3 shows a related art method for controlling concurrent service as shown in FIG. 3, each mobile station MSi˜MSn must set up individual calls to the BSC 102 for each requested service CON.REF 1˜CON.REF 6. The BSC 102, however, only sets up one connection identifier to the MSC 103 for each mobile station.
Providing the current service using the foregoing second generation mobile communication system has various problems. For example, when a method for controlling the concurrent service by a conceptual call processing model for single service in the mobile communication system according to the related art as shown in FIG. 3 is used, the mobile station requires one call for each service. Assuming that one mobile station has the capability of setting up a maximum of 6 services simultaneously, the calls are identified in the base station/base station controller using an identifier such as sr_id or CON.REF on the radio interface. Though the base station/base station controller 102 can control each service option like this, the call control between the BSC and the MSC uses only one SCCP connection identifier (SLR/DLR), regardless of the number of services that one mobile station can make. In other words, if one service is being used, support of that service is stopped to switch to a new requested service, or the call setup request for the new requested service is rejected.
Thus, there is no identifier of each service for one mobile station in the current IOS call setup messages, such as Connection Management (CM) Service Request/Page Response and messages related to supplementary services between the BSC and the MSC of the conventional digital cellular (second generation) mobile communication system. The call is controlled using the SCCP connection identifier (SLR/DLR) allocated to the corresponding mobile station in the initial call setup for the service.
In short, the second generation mobile communication system uses a dimensional single service control method, in which the call is controlled on the basis of the mobile station. That is, the mobile station, the call, and the service are conceptually identified as a single event. Therefore, one mobile station cannot be provided with a plurality of services at the same time. Additionally, the current service must be stopped to provide another service, though a service switching can be carried out by the service negotiation on the radio interface.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.